1. Field of the Invention
The present invention relates to grinding tools, and more particularly grinding tools that can be used in chemical mechanical polishing techniques.
2. Description of the Related Art
Grinding and/or polishing techniques are generally applied to create a desirable surface roughness or planarity on a rigid part, such as metal, ceramic or glass parts, or semiconductor wafers. To this purpose, the grinding and/or polishing techniques use tools having abrasive elements that can wear the rigid surface.
A well known polishing technique is the chemical mechanical polishing (CMP) technique employed in semiconductor fabrication processes. CMP uses corrosive chemical slurry in conjunction with a polishing pad to remove undesired residues and planarize a wafer surface, which can be made of ceramic, silicon, glass, sapphire or metal. CMP can be typically conducted multiple times to planarize wafers. For example, the fabrication process of semiconductor wafers having 28 nm-wide features may require up to 30 CMP steps. After the polishing pad is used over a period of time, the grinding action of the polishing pad may diminish. Accordingly, an additional grinding tool (also called “conditioner”) may be typically used to coarsen the surface of the polishing pad for maintaining an optimal grinding efficiency of the polishing pad.
Conventionally, a cutting rate of the grinding tool may be improved by increasing a distribution density of the abrasive elements provided thereon. This requires increasing the quantity of abrasive elements on the grinding tool, which makes the grinding tool more expensive to manufacture.
Therefore, there is a need for a grinding tool that can have an improved cutting rate, and can be fabricated in a cost-effective manner.